Donald Macdonell Labour Charles Fern Labour The December 1911 Cobar state by-election was scheduled to be held on 16 December 1911 to elect the member for Cobar in the New South Wales Legislative Assembly, following the death of Labour Party MP Donald Macdonell.

[1][2] Macdonell had been absent from parliament because he was unwell, but he was expected to recover.

[3][4] During his absence, a political crisis caused by the resignation of two Labour members resulted in the parliament being prorogued, and he was automatically expelled for non-attendance during an entire session.

[5][6] His seat was declared vacant in September 1911, but he recontested and was elected unopposed at the resulting by-election.

[9][10] The only candidate to contest was Labour's Charles Fern, and he was declared elected at the close of candidate nominations on 2 December 1911.